Which parameter should be maintained at 35 to 40 mm Hg in TBI management?

In the management of traumatic brain injury (TBI), maintaining a target arterial carbon dioxide tension (PaCO2) of 35 to 40 mm Hg is crucial because it plays a significant role in cerebral blood flow and intracranial pressure. The regulation of PaCO2 directly influences the cerebral vascular tone; as CO2 levels increase, vasodilation occurs, leading to increased cerebral blood flow and potentially raising intracranial pressure. Conversely, if PaCO2 decreases (becomes less than 35 mm Hg), this can cause vasoconstriction, reducing cerebral blood flow and oxygen delivery to the brain.

Therefore, maintaining PaCO2 within the 35 to 40 mm Hg range helps to balance intracranial pressure while ensuring adequate cerebral perfusion, which is especially critical in patients suffering from TBI where brain tissue is at risk and requires optimal oxygenation without exacerbating swelling or pressure.

PaO2 is also important in TBI management, as it reflects oxygen levels in the blood. However, the specific target is often focused more on maintaining adequate oxygen saturation rather than a numerical value for PaO2 itself. Blood pressure parameters (systolic and diastolic) are important in ensuring adequate cerebral perfusion pressure, but they